Underwater Fiber Optic Sensing System (UFOSS/FOSS)
iasparliament
July 11, 2026
Prelims: Current events of national and international importance| Science and Tech
Why in News?
India's Defence Research and Development Organisation (DRDO) has initiated indigenous UFOSS projects to strengthen underwater surveillance and maritime security.
Underwater Fiber Optic Sensing System (UFOSS) – It is an advanced underwater surveillance technology that transforms subsea fiber-optic cables into extensive sensor networks.
It is also known as the Fiber Optic Sensing System (FOSS).
Technologies used – Distributed Acoustic Sensing (DAS) and Fiber Bragg Gratings (FBGs).
DAS converts the entire optical fiber into a continuous series of sensing points.
It detects acoustic vibrations and seismic disturbances with exceptionally high spatial resolution—often at intervals of a few millimeters to centimeters.
FBG sensors, on the other hand, measure localized changes in strain, pressure, and temperature by monitoring shifts in reflected wavelengths.
The system is deployed through fixed seabed fiber-optic networks, functioning much like a biological nervous system that continuously transmits information from the ocean floor.
Advantage – Unlike ships, aircraft, or sonobuoys, which provide surveillance only during operational deployments, UFOSS offers 24×7 persistent monitoring without interruption.
This makes it particularly valuable for securing strategic maritime regions.
Applications – Acoustic and hydrographic surveillance.
It can detect and track low-frequency sounds generated by submarines, surface ships, underwater drones, and other marine activities.
Such capabilities significantly enhance maritime domain awareness, anti-submarine warfare (ASW).
Early warning against potential naval threats, particularly in strategically important areas such as the Indian Ocean Region (IOR).
It enables real-time monitoring of offshore oil and gas platforms, underwater pipelines, submarine communication cables, and offshore wind farms by detecting structural strain, leaks, or damage.
The technology also contributes to environmental studies by monitoring oceanographic conditions, underwater earthquakes, and seismic activity, thereby supporting disaster preparedness and marine research.
